Remote Assistance on Chrome OS Part III - NativeMessageHost

chrome/browser/extensions/api/messaging/native_message_host_chromeos.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "extensions/browser/api/messaging/native_message_host.h"
+
+#include <string>
+
+#include "base/command_line.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "extensions/common/constants.h"
+#include "extensions/common/switches.h"
+#include "extensions/common/url_pattern.h"
+#include "ui/gfx/native_widget_types.h"
+#include "url/gurl.h"
+
+namespace extensions {
+
+namespace {
+
+typedef NativeMessageHost::Client Client;
+
+// A simple NativeMesageHost that echoes the received message. It is currently
+// used for testing.
+// TODO(kelvinp): Replace this class once Remote Assistance in process host
+// is implemented.
+class EchoHost : public NativeMessageHost {
+ public:
+  scoped_ptr<NativeMessageHost> static CreateEchoHost(
+      base::WeakPtr<Client> weak_client,
+      int destination_port) {
+    return scoped_ptr<NativeMessageHost>(
+        new EchoHost(weak_client, destination_port));
+  }
+
+  EchoHost(base::WeakPtr<Client> client, int port)
+      : client_(client), port_(port) {}
+
+  virtual void Send(const std::string& json) OVERRIDE {
+    client_->PostMessageFromNativeHost(port_, json);
+  };
+
+ private:
+  base::WeakPtr<Client> client_;
+  int port_;
+
+  DISALLOW_COPY_AND_ASSIGN(EchoHost);
+};
+
+struct BuiltInHost {
+  const char* const name;
+  const char* const* const allowed_origins;
+  int allowed_origins_count;
+  scoped_ptr<NativeMessageHost>(*create_function)(base::WeakPtr<Client>,
+                                                  int port);
+};
+
+// If you modify the list of allowed_origins, don't forget to update
+// remoting/host/it2me/com.google.chrome.remote_assistance.json.jinja2
+// to keep the two lists in sync.
+// TODO(kelvinp): Load the native messaging manifest as a resource file into
+// chrome and fetch the list of allowed_origins from the manifest.
+const char* const kRemotingIt2MeOrigins[] = {
+    "chrome-extension://ljacajndfccfgnfohlgkdphmbnpkjflk/",
+    "chrome-extension://gbchcmhmhahfdphkhkmpfmihenigjmpp/",
+    "chrome-extension://kgngmbheleoaphbjbaiobfdepmghbfah/",
+    "chrome-extension://odkaodonbgfohohmklejpjiejmcipmib/",
+    "chrome-extension://ojoimpklfciegopdfgeenehpalipignm/",
+    "chrome-extension://dokpleeekgeeiehdhmdkeimnkmoifgdd/",
+    "chrome-extension://ajoainacpilcemgiakehflpbkbfipojk/",
+    "chrome-extension://hmboipgjngjoiaeicfdifdoeacilalgc/",
+    "chrome-extension://dhdboenlgbbeohfjeboeooomjmgbejoh/"};

[Sergey Ulanov, 2014/09/25 01:45:22]

This list is different what we have in
com.google.chrome.remote_assistance.json.jinja2

[kelvinp, 2014/09/26 18:12:27]

Done.

+
+static const BuiltInHost kBuiltInHost[] = {
+    {"com.google.chrome.remote_assistance",
+     kRemotingIt2MeOrigins,
+     arraysize(kRemotingIt2MeOrigins),
+     &EchoHost::CreateEchoHost}};

[Sergey Ulanov, 2014/09/25 01:45:22]

Given that this CL contains changes for the It2Me host, why can't we use it here
instead of the fake Echo?
Would it make sense adding separate echo host for tests?

[kelvinp, 2014/09/26 18:12:27]

It2Me host would crash on launching now.  We still need to make some changes in
the ChromotingHostContext in order to launch It2Me host safely.  I can include a
separating echo host for testing in the change when I enable the It2me host.

+
+bool MatchesSecurityOrigin(const BuiltInHost& host,
+                           const std::string& extension_id) {
+  GURL origin(std::string(kExtensionScheme) + "://" + extension_id);
+  for (int i = 0; i < host.allowed_origins_count; i++) {
+    URLPattern allowed_origin(URLPattern::SCHEME_ALL);
+    DCHECK_EQ(URLPattern::PARSE_SUCCESS,
+              allowed_origin.Parse(host.allowed_origins[i]));
+    if (allowed_origin.MatchesSecurityOrigin(origin)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+}  // namespace
+
+scoped_ptr<NativeMessageHost> NativeMessageHost::Create(
+    gfx::NativeView native_view,
+    base::WeakPtr<Client> weak_client,
+    const std::string& source_extension_id,
+    const std::string& native_host_name,
+    int destination_port,
+    bool allow_user_level) {
+  DCHECK(weak_client);
+  scoped_ptr<NativeMessageHost> not_found;
+
+  if (!CommandLine::ForCurrentProcess()
+           ->HasSwitch(switches::kEnableRemoteAssistance)) {
+    return not_found.Pass();
+  }
+
+  for (unsigned int i = 0; i < arraysize(kBuiltInHost); i++) {
+    const BuiltInHost& host = kBuiltInHost[i];
+    std::string name(host.name);
+    if (name == native_host_name &&
+        MatchesSecurityOrigin(host, source_extension_id)) {
+      return (*host.create_function)(weak_client, destination_port);
+    }
+  }
+
+  return not_found.Pass();
+}
+
+}  // namespace extensions